A humidity control apparatus for controlling a humidity of air by using an adsorbent is known conventionally. For example, a combination of a humidity control apparatus of this type and an air conditioner is disclosed in Japanese Patent Application Laid-open No. 8-128681.
To put it concretely, the humidity control apparatus described in the above official gazette includes a disc-shaped absorbing rotor. The adsorbing rotor is disposed astride a flow path for room air and a flow path for outside air and is driven for rotation about its axis. In other words, a portion of the adsorbing rotor is in contact with the room air and the rest of the rotor is in contact with the outside air. The adsorbing rotor is provided with an adsorbent.
In the humidity control apparatus, the outside air is supplied to the adsorbing rotor and moisture in the outside air is adsorbed by the adsorbent. The heated room air is supplied to the adsorbing rotor and the moisture is desorbed from the adsorbent. The humidity control apparatus sends the room air humidified by the adsorbing rotor back into the room.
Problems to be Solved
However, there is a fear that sufficient humidifying performance cannot be obtained in the above humidity control apparatus. This point will be described. In the humidity control apparatus, the heated air is sent to the adsorbing rotor, the moisture is desorbed from the adsorbent, and the desorbed moisture is applied to the air to thereby humidify the air. At this time, the lower a relative humidity of the air introduced into the adsorbing rotor, the likelier it becomes that the moisture is desorbed from the adsorbent.
However, in the humidity control apparatus, the room air of a relatively high absolute humidity is heated and sent to the adsorbing rotor. Therefore, a relative humidity of the room air introduced into the adsorbing rotor after heating cannot be reduced sufficiently and there was a fear that an amount of moisture (i.e., an amount of humidification) desorbed from the adsorbent cannot be secured. If the relative humidity of the room air after heating is reduced so as to secure the amount of humidification, a temperature of the room air after heating has to be increased. As a result, energy required for heating increases and efficiency of the humidity control apparatus is reduced.
The invention has been accomplished in view of the above points and it is an object of the invention to provide a high-efficiency humidity control apparatus in which sufficient humidifying performance can be secured.